1. Field of the Invention
The invention herein relates to vapor release devices/dispensers. More particularly it relates to small portable dispensers to disperse vapors into the surrounding environment.
2. Description of the Prior Art
In recent years there have been numerous applications for small, easily portable liquid and other fluid dispensers. One use of these devices is to provide for dispersion of gases and vapors into the environment. Typical are devices used to alter environmental scents, such as in homes and offices. Another important application, used for a large range of environmental conditions, such as temperature and elevation, is for the release of pheromones. Pheromones are chemical substances released by insects for the purpose of communication.
Chemists have learned to reproduce these chemicals and entomologists have been successful in using them for the management of insects. Insect management requires the release, preferably at constant rates, of minute quantities of pheromones, generally less than 10 milligrams/day, over time periods of up to 12 months. The release of pheromones at these minute rates has been achieved mainly by diffusion of the pheromones through plastic materials, a process which is extremely temperature-sensitive and not field-reliable, since the rate also decreases with time and renders the releaser useless since a minimum threshold of pheromone concentration in the air is not maintained.
Pheromone dispensers have to be economical since in current uses as many as 500-1,000 devices are needed per hectare to control insects. The requirements of low cost, accuracy of delivery, duration of delivery, environmental conditions ranging from sub-freezing to desert-like summer temperatures, elevations from sea level to 10-15,000 feet, and in some instances re-usability, are stringent for practical dispensers.
Dispensers meeting some of these requirements have been described by Maget in U.S. Pat. No. 5,928,194 and Maget, et. al., in U.S. Pat. No. 6,383,165. An embodiment of the latter has been shown to be effective for the control of bark beetles, an insect responsible for the destruction of millions of acres of forest, worldwide. U.S. Pat. No. 6,383,165 is hereby incorporated by reference herein in its entirety, including the detailed description of the various devices used in the delivery of pheromones. In addition, my previously filed provisional application, 60/943,755, filed on Jun. 13, 2007, is also hereby incorporated by reference.
The current device described herein, and in my provisional application ['755], represents an improvement over the previous dispensers inasmuch as they are more economical to produce, easier to fill, include re-usable components, and yet achieve the same performance. Low cost, ease of storage and operation, including continuous delivery over long time periods, such as months, are features and capabilities necessary for commercial dispensers of fragrances as well as pheromones.